Process and apparatus to provide variable drop size ejection with an embedded waveform

Abstract

Described herein is a process and apparatus for driving a droplet ejection device with embedded multi-pulse waveforms. In one embodiment, the process includes generating a multi-pulse waveform that includes drive pulses in predetermined positions. Next, the process includes applying the drive pulses to the actuator and causing the droplet ejection device to eject a first droplet of a fluid. The process also includes applying a second multi-pulse waveform having at least one embedded pulse to the actuator and causing the droplet ejection device to eject a second droplet of the fluid. Each embedded pulse is embedded between predetermined positions of two drive pulses. In some embodiments, the first and second droplets have different droplet sizes and these droplets are ejected at substantially the same effective drop velocity.

1. A method for driving a droplet ejection device having an actuator, comprising:
 generating a first multi-pulse waveform that includes three or more drive pulses in predetermined positions and no drive pulses at locations embedded between the predetermined positions; 
 applying the three or more drive pulses of the first multi-pulse waveform to the actuator to cause the droplet ejection device to eject a first droplet with a first droplet size of a fluid; 
 generating a second multi-pulse waveform that includes no drive pulses in the predetermined positions and one or more drive pulses at locations embedded between the predetermined positions; and 
 applying the one or more drive pulses of the second multi-pulse waveform to the actuator to cause the droplet ejection device to eject a second droplet with a second droplet size of the fluid, wherein the first and second droplets having different droplet sizes, these droplets are ejected at substantially the same effective drop velocity based on the peak voltages of the one or more drive pulses being scaled with respect to the peak voltages of the three or more drive pulses in the predetermined positions. 
 
     
     
       2. The method of  claim 1 , further comprising applying a third waveform having one or more drive pulses fired to cause the droplet ejection device to eject a third droplet of the fluid with a third droplet size in response to applying the third waveform to the actuator. 
     
     
       3. The method of  claim 1 , wherein the second multi-pulse waveform includes only one embedded drive pulse to cause the droplet ejection device to eject the second droplet of the fluid. 
     
     
       4. A method for driving a droplet ejection device having an actuator, comprising:
 generating a first multi-pulse waveform that includes drive pulses in predetermined positions; 
 applying drive pulses of the first multi-pulse waveform to the actuator to cause the droplet ejection device to eject a first droplet with a first droplet size of a fluid; 
 generating a second multi-pulse waveform that includes no drive pulses in the predetermined positions and one or more drive pulses at locations embedded between the predetermined positions; and 
 applying the one or more drive pulses of the second multi-pulse waveform to the actuator to cause the droplet ejection device to eject a second droplet with a second droplet size of the fluid, wherein the first and second droplets have different droplet sizes, wherein the second multi-pulse waveform has two embedded drive pulses and no drive pulses in the predetermined positions to cause the droplet ejection device to eject the second droplet of the fluid. 
 
     
     
       5. A method for driving a droplet ejection device having an actuator, comprising:
 generating a first multi-pulse waveform that includes drive pulses in predetermined positions; 
 applying drive pulses of the first multi-pulse waveform to the actuator to cause the droplet ejection device to eject a first droplet with a first droplet size of a fluid; 
 generating a second multi-pulse waveform that includes no drive pulses in the predetermined positions and one or more drive pulses at locations embedded between the predetermined positions; and 
 applying the one or more drive pulses of the second multi-pulse waveform to the actuator to cause the droplet ejection device to eject a second droplet with a second droplet size of the fluid, wherein the first and second droplets having different droplet sizes, wherein the first multi-pulse waveform has three drive pulses in their predetermined positions to cause the droplet ejection device to eject the first droplet of the fluid. 
 
     
     
       6. The method of  claim 5 , wherein the first droplet size is greater than the second droplet size which is greater than the third droplet size. 
     
     
       7. The method of  claim 5 , wherein a time period from initiation to termination of the first multi-pulse waveform is the same as a time period from initiation to termination of the second multi-pulse waveform. 
     
     
       8. The method of  claim 1 , wherein the effective drop velocity for each of the first and second droplets is approximately 8 m/s with a range from 6 m/s to 11 m/s. 
     
     
       9. The method of  claim 1 , wherein the droplet ejection device comprises a pumping chamber and the actuator operates to vary the pressure of the fluid in the pumping chamber in response to the drive pulses. 
     
     
       10. An apparatus, comprising:
 an actuator to eject droplets of a fluid from a pumping chamber in response to a plurality of waveforms applied to the actuator, wherein the droplets are of different sizes; and 
 drive electronics coupled to the actuator with the drive electronics to drive the actuator with the plurality of waveforms, wherein the drive electronics drives the actuator with:
 a first multi-pulse waveform that includes three or more drive pulses in predetermined positions and no drive pulses at locations embedded between the predetermined positions to cause the actuator to eject a first droplet of the fluid, and 
 a second multi-pulse waveform that includes no drive pulses in the predetermined positions and one or more drive pulses at locations embedded between the predetermined positions, to cause the actuator to eject a second droplet of the fluid, wherein the first and second droplets each have a different droplet size, these droplets are ejected at substantially the same effective drop velocity based on the peak voltages of the one or more drive pulses being scaled with respect to the peak voltages of the three or more drive pulses in the predetermined positions. 
 
 
     
     
       11. The apparatus of  claim 10 , wherein a third waveform has one or more drive pulses fired to cause the droplet ejection device to eject a third droplet of the fluid with a third droplet size in response to applying the third waveform to the actuator. 
     
     
       12. The apparatus of  claim 10 , wherein the second multi-pulse waveform includes only one embedded drive pulse to cause the droplet ejection device to eject the second droplet of the fluid. 
     
     
       13. An apparatus, comprising:
 an actuator to eject droplets of a fluid from a pumping chamber in response to a plurality of waveforms applied to the actuator, wherein the droplets are of different sizes; and 
 drive electronics coupled to the actuator with the drive electronics to drive the actuator with the plurality of waveforms, wherein the drive electronics drives the actuator with:
 a first multi-pulse waveform that includes drive pulses in predetermined positions to cause the actuator to eject a first droplet of the fluid, and 
 
 
       a second multi-pulse waveform that includes no drive pulses in the predetermined positions and one or more drive pulses at locations embedded between the predetermined positions, to cause the actuator to eject a second droplet of the fluid, wherein the first and second droplets each have a different droplet size, wherein the second multi-pulse waveform has two embedded drive pulses and no drive pulses in the predetermined positions to cause the droplet ejection device to eject the second droplet of the fluid. 
     
     
       14. An apparatus, comprising:
 an actuator to eject droplets of a fluid from a pumping chamber in response to a plurality of waveforms applied to the actuator, wherein the droplets are of different sizes; and 
 drive electronics coupled to the actuator with the drive electronics to drive the actuator with the plurality of waveforms, wherein the drive electronics drives the actuator with:
 a first multi-pulse waveform that includes drive pulses in predetermined positions to cause the actuator to eject a first droplet of the fluid, and 
 
 
       a second multi-pulse waveform that includes no drive pulses in the predetermined positions and one or more drive pulses at locations embedded between the predetermined positions, to cause the actuator to eject a second droplet of the fluid, wherein the first and second droplets each have a different droplet size, wherein the first multi-pulse waveform has three drive pulses in their predetermined positions to cause the droplet ejection device to eject the first droplet of the fluid. 
     
     
       15. The apparatus of  claim 14 , wherein the first droplet size is greater than the second droplet size which is greater than the third droplet size. 
     
     
       16. A printhead, comprising:
 an ink jet module that comprises, 
 an actuator to eject droplets of a fluid from a pumping chamber in response to a plurality of waveforms applied to the actuator, wherein the droplets are of different sizes; and 
 drive electronics coupled to the actuator with the drive electronics to drive the actuator with the plurality of waveforms, wherein the drive electronics drives the actuator with:
 a first multi-pulse waveform that includes three or more drive pulses in predetermined positions and no drive pulses at locations embedded between the predetermined positions to cause the actuator to eject a first droplet of the fluid, and a second multi-pulse waveform that includes no drive pulses in the predetermined positions and one or more drive pulses at locations embedded between the predetermined positions, to cause the actuator to eject a second droplet of the fluid, wherein the first and second droplets each have a different droplet size, these droplets are ejected at substantially the same effective drop velocity based on the peak voltages of the one or more drive pulses being scaled with respect to the peak voltages of the three or more drive pulses in the predetermined positions. 
 
 
     
     
       17. The printhead of  claim 16 , wherein a third waveform has one or more drive pulses fired to cause the droplet ejection device to eject a third droplet of the fluid with a third droplet size in response to applying the third waveform to the actuator. 
     
     
       18. The printhead of  claim 16 , wherein the second multi-pulse waveform includes only one embedded drive pulse to cause the droplet ejection device to eject the second droplet of the fluid. 
     
     
       19. A printhead, comprising:
 an ink jet module that comprises, 
 an actuator to eject droplets of a fluid from a pumping chamber in response to a plurality of waveforms applied to the actuator, wherein the droplets are of different sizes; and 
 drive electronics coupled to the actuator with the drive electronics to drive the actuator with the plurality of waveforms, wherein the drive electronics drives the actuator with:
 a first multi-pulse waveform that includes drive pulses in predetermined positions to cause the actuator to eject a first droplet of the fluid, and 
 
 
       a second multi-pulse waveform that includes no drive pulses in the predetermined positions and one or more drive pulses at locations embedded between the predetermined positions, to cause the actuator to eject a second droplet of the fluid, wherein the first and second droplets each have a different droplet size, wherein the second multi-pulse waveform has two embedded drive pulses and no drive pulses in the predetermined positions to cause the droplet ejection device to eject the second droplet of the fluid. 
     
     
       20. The printhead of  claim 16 , wherein the first multi-pulse waveform has three drive pulses in their predetermined positions to cause the droplet ejection device to eject the first droplet of the fluid. 
     
     
       21. The printhead of  claim 16 , wherein the ink jet module further comprises:
 a carbon body, a stiffener plate, a cavity plate, a first flex print, a nozzle plate, an ink fill passage, and a second flex print. 
 
     
     
       22. A method for driving a droplet ejection device having an actuator, comprising:
 generating a first multi-pulse waveform that includes one or more drive pulses in at least one of three predetermined positions for drive pulses and one or more additional embedded pulses in at least one of two embedded positions with each embedded pulse in the embedded position being embedded between two predetermined positions; and 
 applying the one or more drive pulses and the one or more additional embedded pulses of the first multi-pulse waveform to the actuator to cause the droplet ejection device to eject a first droplet with a first droplet size of a fluid, wherein peak voltages of the one or more embedded drive pulses are scaled with respect to peak voltages of the one or more drive pulses. 
 
     
     
       23. The method of  claim 22 , further comprising:
 generating a second multi-pulse waveform that includes zero or more drive pulses that are in the predetermined positions and zero or more additional pulses that are each located in the second multi-pulse waveform at locations embedded between the predetermined positions; and 
 applying drive pulses of the second multi-pulse waveform to the actuator to cause the droplet ejection device to eject a second droplet with a second droplet size of the fluid in response to the pulses of the second multi-pulse waveform. 
 
     
     
       24. The method of  claim 23 , further comprising applying a third waveform having one or more drive pulses fired to cause the droplet ejection device to eject a third droplet of the fluid with a third droplet size in response to applying the third waveform to the actuator. 
     
     
       25. The method of  claim 24 , wherein the first, second, and third droplets have different droplet sizes and are ejected at substantially the same effective drop velocity.